Loudspeaker and enclosure assembly

ABSTRACT

A loudspeaker and enclosure assembly in which a small electromagnetic speaker is mounted in a cylindrical sheet metal can with one open and one closed end, the speaker having a cone spaced from and confronting the open end of the can and being mounted on a bracket mechanically affixed to the side wall of the can. The portion of the can between the closed end and the loudspeaker is substantially filled with a coil of corrugated paper forming channels parallel to the axis of the cylindrical can, and a hollow cylinder of corrugated paper surrounds the loudspeaker in abutment with the interior surface of the can. A screen extends over the open end of the can.

1 1 May 20, 1975 i 1 LOUDSPEAKER AND ENCLOSURE ASSEMBLY 1.436.065 3/1966 France 181/31 B Primary Examiner-Stephen J. Tomsky 76 l t T th R.O' k, 1085f l 1 men or 22: a m gg Attorney, Agent, or FlrmBurme1ster, York.

Palmatier, Hamby & Jones [22] Filed: Mar. 6, 1974 [211 Appl. No.: 448,672 57 ABSTRACT A loudspeaker and enclosure assembly in which a [52] US. Cl. 181/155; 181/150; 181/151; small electromagnetic speaker is mounted in a cylin- 181/153 drical sheet metal can with one open and one closed [51] Int. Cl. GlOk 13/00; H04r 1/28 end, the speaker having a cone spaced from and con- [58] Field of Search 181/31 B, 155, 151, 153, fronting the open end of the can and being mounted 181/150, 148 on a bracket mechanically affixed to the side wall of the can. The portion of the can between the closed [56] References Cited end and the loudspeaker is substantially filled with a UNITED STATES PATENTS coil of corrugated paper forming channels parallel to 3 443 660 5/1969 Vin/a e a] 18 B the axis of the cylindrical can, and a hollow cylinder 3 642091 2/1972 Nohara e151111111111111 181 31 B of Corrugated Paler Surrounds the loudspeaker 3:684:05] 8/1972 Hopkins.........:1.......:.......:: 181/31 B abutment with the interior Surface of A screen extends over the open end of the can. FOREIGN PATENTS OR APPLICATIONS 423,291 7 1947 ltaly 181/31 B 5 Claims, 3 Drawing Figures l i 1O 7 l :1 i v 7 A LOUDSPEAKER AND ENCLOSURE ASSEMBLY The presentinvention relates to loudspeaker and enclosure assemblies, particularly for use with small and low power audio sources, such as portable transisto radios.

Prior to the present invention there have been many loudspeaker and enclosure assemblies available for relatively high power audio sources and at relatively high costs. Such assemblies have generally been large, and bulky, and the total sound emitted from such assem blies has been radiated through an opening in the enclosure. I

It is an object of the present invention to provide a loudspeaker and enclosure assembly using a loudspeaker with a relatively small radiating cone in which the walls of the enclosure as well as the cone contribute to the radiated sound.

It is a further object of the present invention to utilize a can, such as used for the merchandizing of beverages, as the enclosure for a loudspeaker.

Many of the loudspeaker and enclosure assemblies known in the past have resulted in a mechanical resonance for the loudspeaker system which is substantially higher than the mechanical resonance of the loudspeaker in free air. It is an object of the present invention to provide a loudspeaker and enclosure assembly in which the mechanical resonance of the loudspeaker is substantially unchanged when placed within the enclosure, and hence radiation of the lower frequency sounds from the loudspeaker is substantially unimpaired when the loudspeaker is placed within the enclosure.

In accordance with the present invention, a loudspeaker is placed within a cylindrical sheet metal can, the speaker having a cone diverging toward the open end of the can but spaced therefrom. The closed end of the can is provided with a mass of fibrous material which forms a plurality of linear channels which are disposed parallel to the cylindrical axis of the can. Further, a fibrous cylinder disposed between the perimeter of the loudspeaker and the inner surface of the cylindrical can also provides a plurality of parallel channels between the opening and the side of the loudspeaker cone opposite the opening.

The present invention will be more fully understood from the following description, particularly when taken in the light of the drawings, in which:

FIG. 1 is a vertical sectional view of a loudspeaker and enclosure assembly constructed according to the teachings of the present invention;

. FIG. 2 is a sectional view taken along the line 22 of FIG. 1; and

FIG. 3 is a sectional view taken along the line 33 of FIG. 1.

As illustrated in the figures, the loudspeaker has a housing in the form of a cylindrical sheet metal container, such as the l2-ounce cans used to dispense beverages. The housing 10 is closed at one end by an end wall 12 and has an opening 14 at the other end, the opening 14 extending across the entire end of the can. The cylindrical wall of the can is designated 16 in the drawings.

An elongated rectangular sheet or strip of fibrous material, designated 18 is wound into a loose cylindrical form and disposed in the can 10 in abutment with the end wall 12. The strip of fibrous material is preferably paper with a flat backing strip 20 and a corrugated strip 22 cemented thereon or otherwise secured to the flat backing strip 20, thereby providing a plurality of relatively small channels 24 between the flat backing strip 20 andthe corrugated strip 22. The loosely wound cylinder formed by this elongated strip 18 occupies the lower portion of the can 10, and substantially divides this portion of the can 10 into a plurality of substantially parallel vertical channels, the channels including the channels 24 and channels formed between the exterior surfaces of the corrugated strip 22 and the confronting surface of the flat strip 20, these channels being designated 26. The loosely wound strip 18 terminates at its end opposite the wall 12 on a substantially flat plane, and a bracket 28 is mounted in the open end of the can 10 and has a central portion 30 which abuts the loosely wound strip 18 at this plane, the plane being designated 32 in FIG. 1.

The bracket 28 is provided with right angle bends 34 at opposite ends of the central portion thereof, and a pair of parallel legs 36 and 38 extend from the central portion 30 of the bracket toward the opening 14. The bracket 28 is formed of the narrow strip of metal and the legs 36 and 38 are held in abutment with the inner surface of the wall 16 of the can 10 by wedging the ends of the legs 36 and 38 against a protruding lip 39 which extends about the inner surface of the can 10 at its open end, the central portion 30 of the bracket 28 being urged against the wound strip 18. The bracket 28 supports an electromagnetic loudspeaker 40. The loudspeaker 40 has a frame 42 with a hub 44 mounted on the center of the central portion 30 of the bracket 28. The frame 42 also supports the perimeter of a cone 46 which diverges in a direction toward the opening 14 of the can 10.

A corrugated cylinder 48 is disposed coaxially in the can 10 in the region of the legs 36 and 38 of the bracket 28, the cylinder 48 being wedged between the perimeter of the frame 42 of the loudspeaker 40 and the inner surface of the wall 16 of the can 10. The cylinder 48 is formed by the same material utilized for the strip 18, the flat strip 20 abutting the surface of the can 10, and the corrugated strip 23 abutting the perimeter of the frame 42 of the loudspeaker 40, thereby providing a plurality of channels 50 and 52 formed between the flat strip 20 and corrugated strip 23, and between the pe-' rimeter of the rim 42 and the corrugated strip 23, respectively. A flat screen 54 extends over the opening 14 to prevent foreign objects from entering the can 10 or damaging the cone 46 of the loudspeaker 40.

The bracket 28 mounts the loudspeaker at a distance from the opening 14 of the can 10. The loudspeaker is thus further protected from foreign objects, and positioned well within the can.

The strip 18 of fibrous material, and the strip 48 of fibrous material are light relatively flexible members. I-Ience, sound traveling through the channels 24 and 26, or 50 and 52 are coupled to the wall 16 of the casing 10, since the strips 20 and 22 will deflect outwardly for compressional waves and contract inwardly for rarification waves. However, the channels 24 and 26 limit sound waves from traveling through multiple paths and the fact that the speaker 40 is not seen within the opening 14 of the can 10, but is coupled to the ambient atmosphere through the channels 50 and 52 in the cylinder 48 of fibrous material, prevents changes in the mechanical resonance of the loudspeaker due to the small size of the enclosure formed by the can or housing 10. Accordingly, the applicant has achieved a substantially greater volume of sound due to the radia tion of sound by the entire can 10, and has avoided mechanical resonance by providing the channels 24, 26, 50 and 52 within the container for can 10. Further, the base response of the loudspeaker 40 is maintained. by avoiding an increase in the mechanical resonance of the speaker system from that of the speaker itself by the foregoing construction. 1

In one particular embodiment of the present invention, the can 10 is a 12-ounce can originally utilized by the G. Heileman Brewing Company as a container for beer, the can being approximately inches in length and having a diameter of approximately 2% inches. The loudspeaker has a frame measuring 2% inches in diameter and a cone measuring 2 inches in diameter. The depth of the frame is approximately inch. The bracket 28 mounts the loudspeaker a distance of approximately 1 inch from the screen 54 at the opening 14 of the can 10. The loosely wound cylindrical coil of fibrous material has an axis coaxially with the can measuring approximately 2 /8 inches, and the fibrous material has a thickness of approximately one-sixteenth inch and contains four corrugations per linear inch along the longitudinal axis of the strip 18 before winding of the strip into the cylinder. The flat strip 20 and corrugated strip 22 are formed of paper.

The loudspeaker 40 has a pair of terminals 56 mounted on the frame 42 thereof, and the terminals are connected to a pair of wires 58 which extend downwardly through the strip 18 and an aperture 60 to a connector 62. A rubber grommet 64 surrounds the aperture 60 and protects the wires 58.

The speaker may be connected to the output of any audio device, such as a radio, phonograph; or the like. It is designed to function effectively and at substantial volume when connected to the earphone output of a transistor radio, for example.

The inventor has provided a loudspeaker which achieves substantial volume utilizing a very small electromagnetic speaker. Further, the loudspeaker and enclosure achieve a frequency response range substantially undiminished by the small size of the enclosure. Additionally, the inventor has been able to'utilize a scrap product for use as a loudspeaker and enclosure while achieving a fidelity, and frequency response, and amplitude of sound from a very small loudspeaker which is unknown to the art.

Those skilled in the art will devise uses for the present invention not here set forth, and it is therefore intended that the scope of the present invention be not limited by the foregoing disclosure, but rather only by the appended claims.

The invention claimed is:

1. A loudspeaker and enclosure assembly comprising, in combination, a cylindrical container having one closed end and an open end, an elongated sheet of fibrous material coiled into a loosely wound cylinder disposed in the container abutting the closed end and partially filling the container, a flat elongated strip having two normal bends forming a central portion disposed in abutment with the wound sheet of fibrous material and a pair oflegs of equal length extending from the central portion of the strip towardthe open end of the container in abutment with the side of the container, a loudspeaker having a frame and vibratile cone, the frame being mounted on the strip and the cone being disposed coaxially of the container and diverging toward the open end of the container, and a cylinder of fibrous material disposed within the container and extending from the central portion of the strip to the open end of the container, said cylinder of fibrous material being disposed between the container and the frame of the loudspeaker and abutting said frame.

2. A loudspeaker according to claim 1 in combination with a wire screen extending over the open end of the container to permit sound waves to traverse the opening and protect the loudspeaker from foreign objects.

3. A loudspeaker and enclosure assembly according to claim 1 wherein the sheet of fibrous material consists of paper and has two layers, one of said layers being substantially flat and the other layer being corrugated and secured on the first layer, the corrugations forming channels parallel to the cylindrical axis of the container.

4. A loudspeaker according to claim 3 wherein the cylinder of fibrous material consists of paper and has two layers, one of said layers being substantially flat and the other layer being corrugated and secured on the first layer, the corrugations forming channels parallel to the cylindrical axis of the can.

5. A loudspeaker and enclosure assembly comprising the combination of claim 1 wherein the cylindrical container is constructed of sheet metal. 

1. A loudspeaker and enclosure assembly comprising, in combination, a cylindrical container having one closed end and an open end, an elongated sheet of fibrous material coiled into a loosely wound cylinder disposed in the container abutting the closed end and partially filling the container, a flat elongated strip having two normal bends forming a central portion disposed in abutment with the wound sheet of fibrous material and a pair of legs of equal length extending from the central portion of the strip toward the open end of the container in abutment with the side of the container, a loudspeaker having a frame and vibratile cone, the frame being mounted on the strip and the cone being disposed coaxially of the container and diverging toward the open end of the container, and a cylinder of fibrous material disposed within the container and extending from the central portion of the strip to the open end of the container, said cylinder of fibrous material being disposed between the container and the frame of the loudspeaker and abutting said frame.
 2. A loudspeaker according to claim 1 in combination with a wire screen extending over the open end of the container to permit sound waves to traverse the opening anD protect the loudspeaker from foreign objects.
 3. A loudspeaker and enclosure assembly according to claim 1 wherein the sheet of fibrous material consists of paper and has two layers, one of said layers being substantially flat and the other layer being corrugated and secured on the first layer, the corrugations forming channels parallel to the cylindrical axis of the container.
 4. A loudspeaker according to claim 3 wherein the cylinder of fibrous material consists of paper and has two layers, one of said layers being substantially flat and the other layer being corrugated and secured on the first layer, the corrugations forming channels parallel to the cylindrical axis of the can.
 5. A loudspeaker and enclosure assembly comprising the combination of claim 1 wherein the cylindrical container is constructed of sheet metal. 